Generally, manhole, sanitary sewer and catch basin systems have previously been described. These systems typically include a concrete base having one or more segments that fit together to form a riser or chimney; a precast concrete cone that rests on top of the uppermost base segment; rectangular or cylindrical adjusting rings aligned and stacked on top of the cone; a steel manhole cover support frame or catch basin support frame, and a steel manhole cover or catch basin grate. During construction of roadways or streets a rubber or other sealing material may be positioned between the joints or seams of the concrete base, cone, and adjusting rings to restrict the flow of fluids either into or out of the manhole or catch basin system.
Although these seals may initially restrict the flow of fluids between the joints, over time, these systems are often subjected to many freeze/thaw cycles, vehicle weight and impact, erosion or other influences which weaken the integrity of the system and deteriorates the sealed joints in the system. Since water finds the path of least resistance, any gap or crack will allow water to works its way through and eventually will likely create leaks large enough for water, dirt, sand, and other debris to seep into the system. Additional freeze/thaw cycles will further deteriorate the system and potentially require significant repair or replacement to the system.
Additionally, it may be desirable to restrict the commingling of sewage and refuse with rain water, snow melts, and other water runoff. Water from rain and melting snow runoff can seep through the ground and enter the system through seams between the cone and the adjusting rings and between the adjusting rings and the cover support frame. Seepage of water may also cause soil erosion around the system. As water enters into the system through any imperfection in the system, the water also carries the surrounding soil into the system, eroding the soil around the system, and eventually causing soil at the ground level to collapse.
Prior devices have been described that attempt to create an impenetrable barrier between the annular adjusting rings and an interior of the system. For example, elastomeric bands, expandable sleeves, and rubber like rope have been described as possible seals for the adjusting rings. Repetitive heavy impact, ground shifting and freeze/thaw cycles all tend to affect the ability of water to penetrate these prior sealing devices. Further, no known prior device describes an apparatus that provides an impenetrable barrier that includes a cover that may be separately removed from the system after the barrier, adjusting rings, and support frame are installed. Also, no known prior device describes a secondary cover that seals and restricts water flow into the interior of the system when the water table rises above the top edge of the seal or during temporary influx of water levels or flooding above ground.